The U.N. Security Council has strongly condemned the siege of a Palestinian refugee camp in the Syrian capital by self-proclaimed Islamic State militants and fighters from the Nusra Front. In an emergency session Monday, the Council called for the protection and safe evacuation of civilians and access for humanitarian aid workers to the approximately 18,000 people still living in the Yarmouk camp.

Reports emerged last week that fighters from the two armed groups had seized large parts of the camp on the outskirts of Damascus.

The head of the U.N. Relief and Works Agency for Palestinian Refugees (UNRWA), Pierre Krähenbühl, separately briefed both the U.N. Secretary-General and the Security Council via a video link from Amman, Jordan on the developments. Afterwards, he told reporters that the situation in the Yarmouk camp - which was already dire - has deteriorated further and very few civilians have been able to leave.

“There are, we believe a few hundreds maybe, maximum, that have been able to leave the camp that we at least can confirm. Yesterday we have been assisting just under a hundred of them that had arrived in one of the neighborhoods just beside Yarmouk, he said.

He said prior to the 2011 conflict, Yarmouk was home to about 170,000 Palestinian refugees; only about 10 percent of them remain.

Yarmouk has been under Syrian government siege for nearly two years and has received only sporadic aid deliveries. Last Wednesday, media reports said Islamic State and associated armed groups stormed the camp, taking control of most of it.

Krähenbühl described the situation as "fluid and volatile." “I think that we can safely say that a significant percentage of the civilians who were inside the camp are now in areas that are controlled by these armed groups,” he said.

Palestinian U.N. Ambassador Riyad Mansour urged parties to the conflict to spare the Palestinians, saying they have avoided involvement in Syria’s civil war.

“We were appealing to all parties - government and opposition -- not to get our people involved and to add more agonies to their on-going tragedy,” said Mansour.

FILE - Residents line up to receive humanitarian aid at the Palestinian refugee camp of Yarmouk, in Damascus, Syria, March 11, 2015.

The U.N. says before the war started there were about 560,000 Palestinian refugees in Syria. That number has dropped by about 100,000. The UNRWA chief said 95 percent of Palestinians still in the country now fully depend on his agency for assistance.

The U.N. Security Council called for safe passage and evacuation of civilians from Yarmouk and said it would look into “further measures” that could be taken to provide the necessary protection and assistance to civilians there.